1. Field of the Invention
The invention relates to a focus-adjustable LED flashlight, more particularly to a focus-adjustable LED flashlight including an LED light-emitting unit and a positive lens that is adjustable to move relative to the LED light-emitting unit.
2. Description of the Related Art
In recent years, light-emitting diode (LED) lamps have become popular for use as a light source for a flashlight. However, since the conventional flashlight uses a parabolic reflector for collecting and directing the LED light and since the emitted angle of the LED light is not the same as a point light source, a considerable portion of the LED light cannot be collected and directed by the parabolic reflector. Hence, the intensity of the LED light focused through adjustment of the position of the LED lamp relative to the parabolic reflector is relatively poor.